The present invention relates, generally, to an imaging system for an electrophotographic reproduction device and, more particularly, to an imaging system which forms, on a recording medium, a composite image of an original document, the exposed document image being modified by additional information added thereto by a supplemental imaging mechanism.
It is often desirable, when reproducing documents to modify the original content by, for example, adding supplemental text or pictorial information. Typical examples are the insertion of a company logo or address on each copy made. Some documents may also require identification control numbers, or page numbers, to be affixed thereto.
Composite images are formed in the known prior art by a variety of techniques. U.S. Pat. No. 4,167,324 (Wu) issued Sept. 11, 1979 discloses a technique whereby a latent image of an original document is formed on a photoreceptor by a light lens system along a first optical path while a modulated light beam input is directed along a second optical path to the surface of a stratified stylus belt. The belt is placed in proximity to the photoreceptor and acts to provide a charge pattern on the previously formed latent image in conformity with the information in the modulated laser input.
A second technique is disclosed in U.S. Pat. No. 4,385,822 (Kanbo) issued May 31, 1983. As disclosed therein, an electromagnetic recording medium is used which enables formation of a first electrostatic latent image in one layer thereof, as well as a second, magnetic latent image in a second layer thereof. The formation of the two images are synchronized and the composite latent image is subsequently developed by a specially designed developing device.
A third technique is to utilize an ion writing station as described in IBM Technical Disclosure Bulletin, Vol. 22, No. 12, May 1980, pp. 5270-5271. For this technique, a latent electrostatic image of the original document is formed by a light/lens optical arrangement. At a downstream position an ion writing station deposits a selected charge pattern on an already discharged portion of the latent image. This charge pattern conforms to the information desired to be added to the original document image.
These prior art techniques are subject to various problems and suffer from various disadvantages. The laser modulated systems are expensive and require significant space to house the various optical components. The ion generator and electromagnetic techniques are costly to implement and require stringent alignment procedures.
According to the present invention, there is provided a compact, inexpensive annotator device which modifies an original document image by adding or replacing information thereto. More particularly, the invention is directed to an apparatus for forming a composite latent image on a photosensitive surface, said composite image corresponding to informational areas contained on an original document and information added thereto, the apparatus comprising:
illumination and imaging means for forming a first latent image of an original document on a photosensitive recording medium, and
annotator means adjacent said recording member for imposing a second latent image pattern within said first latent image area, said annotator means comprising:
an illumination source, partially enclosed by a light-collimating reflector,
a two-dimensional lens array,
a light modulating device positioned between said illumination source and said lens array and optically aligned therewith, and
control means for periodically energizing said illumination source and for applying a modulation pattern to said modulating device,
whereby a modulated light pattern is projected by said lens array onto said recording medium forming said second latent image information pattern.